QgsGeometry* QgsMapToolOffsetCurve::createOriginGeometry( QgsVectorLayer* vl, const QgsPointLocator::Match& match, QgsFeature& snappedFeature )
{
  if ( !vl )
  {
    return 0;
  }

  mMultiPartGeometry = false;
  //assign feature part by vertex number (snap to vertex) or by before vertex number (snap to segment)
  int partVertexNr = match.vertexIndex();

  if ( vl == currentVectorLayer() && !mForceCopy )
  {
    //don't consider selected geometries, only the snap result
    return convertToSingleLine( snappedFeature.geometryAndOwnership(), partVertexNr, mMultiPartGeometry );
  }
  else //snapped to a background layer
  {
    //if source layer is polygon / multipolygon, create a linestring from the snapped ring
    if ( vl->geometryType() == QGis::Polygon )
    {
      //make linestring from polygon ring and return this geometry
      return linestringFromPolygon( snappedFeature.geometry(), partVertexNr );
    }

    //for background layers, try to merge selected entries together if snapped feature is contained in selection
    const QgsFeatureIds& selection = vl->selectedFeaturesIds();
    if ( selection.size() < 1 || !selection.contains( match.featureId() ) )
    {
      return convertToSingleLine( snappedFeature.geometryAndOwnership(), partVertexNr, mMultiPartGeometry );
    }
    else
    {
      //merge together if several features
      QgsFeatureList selectedFeatures = vl->selectedFeatures();
      QgsFeatureList::iterator selIt = selectedFeatures.begin();
      QgsGeometry* geom = selIt->geometryAndOwnership();
      ++selIt;
      for ( ; selIt != selectedFeatures.end(); ++selIt )
      {
        QgsGeometry* combined = geom->combine( selIt->geometry() );
        delete geom;
        geom = combined;
      }

      //if multitype, return only the snapped to geometry
      if ( geom->isMultipart() )
      {
        delete geom;
        return convertToSingleLine( snappedFeature.geometryAndOwnership(), match.vertexIndex(), mMultiPartGeometry );
      }

      return geom;
    }
  }
}

QgsFeatureList QgsClipboard::transformedCopyOf( QgsCoordinateReferenceSystem destCRS )
{
  QgsFeatureList featureList = copyOf();
  QgsCoordinateTransform ct( crs(), destCRS );

  QgsDebugMsg( "transforming clipboard." );
  for ( QgsFeatureList::iterator iter = featureList.begin(); iter != featureList.end(); ++iter )
  {
    iter->geometry()->transform( ct );
  }

  return featureList;
}

bool QgsMemoryProvider::addFeatures( QgsFeatureList & flist )
{
  // TODO: sanity checks of fields and geometries
  for ( QgsFeatureList::iterator it = flist.begin(); it != flist.end(); ++it )
  {
    mFeatures[mNextFeatureId] = *it;
    QgsFeature& newfeat = mFeatures[mNextFeatureId];
    newfeat.setFeatureId( mNextFeatureId );
    it->setFeatureId( mNextFeatureId );

    // update spatial index
    if ( mSpatialIndex )
      mSpatialIndex->insertFeature( newfeat );

    mNextFeatureId++;
  }

  updateExtent();

  return true;
}

bool QgsWFSProvider::addFeatures( QgsFeatureList &flist )
{
  //create <Transaction> xml
  QDomDocument transactionDoc;
  QDomElement transactionElem = createTransactionElement( transactionDoc );
  transactionDoc.appendChild( transactionElem );

  //find out typename from uri and strip namespace prefix
  QString tname = mShared->mURI.typeName();
  if ( tname.isNull() )
  {
    return false;
  }
  removeNamespacePrefix( tname );

  //Add the features
  QgsFeatureList::iterator featureIt = flist.begin();
  for ( ; featureIt != flist.end(); ++featureIt )
  {
    //Insert element
    QDomElement insertElem = transactionDoc.createElementNS( QgsWFSConstants::WFS_NAMESPACE, "Insert" );
    transactionElem.appendChild( insertElem );

    QDomElement featureElem = transactionDoc.createElementNS( mApplicationNamespace, tname );

    QgsAttributes featureAttributes = featureIt->attributes();
    int nAttrs = featureAttributes.size();
    for ( int i = 0; i < nAttrs; ++i )
    {
      const QVariant& value = featureAttributes.at( i );
      if ( value.isValid() && !value.isNull() )
      {
        QDomElement fieldElem = transactionDoc.createElementNS( mApplicationNamespace, mShared->mFields.at( i ).name() );
        QDomText fieldText = transactionDoc.createTextNode( value.toString() );
        fieldElem.appendChild( fieldText );
        featureElem.appendChild( fieldElem );
      }
    }

    //add geometry column (as gml)
    const QgsGeometry* geometry = featureIt->constGeometry();
    if ( geometry != nullptr )
    {
      QDomElement geomElem = transactionDoc.createElementNS( mApplicationNamespace, mShared->mGeometryAttribute );
      QgsGeometry the_geom( *geometry );
      // convert to multi if the layer geom type is multi and the geom is not
      if ( QGis::isMultiType( this->geometryType( ) ) && ! the_geom.isMultipart( ) )
      {
        the_geom.convertToMultiType();
      }
      QDomElement gmlElem = QgsOgcUtils::geometryToGML( &the_geom, transactionDoc );
      if ( !gmlElem.isNull() )
      {
        gmlElem.setAttribute( "srsName", crs().authid() );
        geomElem.appendChild( gmlElem );
        featureElem.appendChild( geomElem );
      }
    }

    insertElem.appendChild( featureElem );
  }

  QDomDocument serverResponse;
  bool success = sendTransactionDocument( transactionDoc, serverResponse );
  if ( !success )
  {
    return false;
  }

  if ( transactionSuccess( serverResponse ) )
  {
    //transaction successful. Add the features to the cache
    QStringList idList = insertedFeatureIds( serverResponse );
    QStringList::const_iterator idIt = idList.constBegin();
    featureIt = flist.begin();

    QVector<QgsWFSFeatureGmlIdPair> serializedFeatureList;
    for ( ; idIt != idList.constEnd() && featureIt != flist.end(); ++idIt, ++featureIt )
    {
      serializedFeatureList.push_back( QgsWFSFeatureGmlIdPair( *featureIt, *idIt ) );
    }
    mShared->serializeFeatures( serializedFeatureList );

    // And now set the feature id from the one got from the database
    QMap< QString, QgsFeatureId > map;
    for ( int idx = 0; idx < serializedFeatureList.size(); idx++ )
      map[ serializedFeatureList[idx].second ] = serializedFeatureList[idx].first.id();

    idIt = idList.constBegin();
    featureIt = flist.begin();
    for ( ; idIt != idList.constEnd() && featureIt != flist.end(); ++idIt, ++featureIt )
    {
      if ( map.find( *idIt ) != map.end() )
        featureIt->setFeatureId( map[*idIt] );
    }

    return true;
  }
  else
  {
//.........这里部分代码省略.........

void QgsClipboard::replaceWithCopyOf( const QgsFieldMap& fields, QgsFeatureList& features )
{

  // Replace the QGis clipboard.
  mFeatureClipboard = features;
  QgsDebugMsg( "replaced QGis clipboard." );

  // Replace the system clipboard.

  QStringList textLines;
  QStringList textFields;

  // first do the field names
  textFields += "wkt_geom";
  for ( QgsFieldMap::const_iterator fit = fields.begin(); fit != fields.end(); ++fit )
  {
    textFields += fit->name();
  }
  textLines += textFields.join( "\t" );
  textFields.clear();


  // then the field contents
  for ( QgsFeatureList::iterator it = features.begin(); it != features.end(); ++it )
  {
    QgsAttributeMap attributes = it->attributeMap();


    // TODO: Set up Paste Transformations to specify the order in which fields are added.

    if ( it->geometry() )
      textFields += it->geometry()->exportToWkt();
    else
    {
      QSettings settings;
      textFields += settings.value( "qgis/nullValue", "NULL" ).toString();
    }

    // QgsDebugMsg("about to traverse fields.");
    //
    for ( QgsAttributeMap::iterator it2 = attributes.begin(); it2 != attributes.end(); ++it2 )
    {
      // QgsDebugMsg(QString("inspecting field '%1'.").arg(it2->toString()));
      textFields += it2->toString();
    }

    textLines += textFields.join( "\t" );
    textFields.clear();
  }

  QString textCopy = textLines.join( "\n" );

  QClipboard *cb = QApplication::clipboard();

  // Copy text into the clipboard

  // With qgis running under Linux, but with a Windows based X
  // server (Xwin32), ::Selection was necessary to get the data into
  // the Windows clipboard (which seems contrary to the Qt
  // docs). With a Linux X server, ::Clipboard was required.
  // The simple solution was to put the text into both clipboards.

  // The ::Selection setText() below one may need placing inside so
  // #ifdef so that it doesn't get compiled under Windows.
  cb->setText( textCopy, QClipboard::Selection );
  cb->setText( textCopy, QClipboard::Clipboard );

  QgsDebugMsg( QString( "replaced system clipboard with: %1." ).arg( textCopy ) );
}

//.........这里部分代码省略.........
  // append geometry column name
  if ( !mGeometryColName.isEmpty() )
  {
    if ( !first )
    {
      statement += ',';
      values += ',';
    }

    statement += QString( "%1" ).arg( mGeometryColName );

    values += QString( "db2gse.%1(CAST (%2 AS BLOB(2M)),%3)" )
              .arg( mGeometryColType,
                    QString( "?" ),
                    QString::number( mSRId ) );
  }

  QgsDebugMsg( statement );
  QgsDebugMsg( values );
  statement += ") VALUES (" + values + ')';
  QgsDebugMsg( statement );

  QgsDebugMsg( "Prepare statement" );
  // use prepared statement to prevent from sql injection
  if ( !query.prepare( statement ) )
  {
    QString msg = query.lastError().text();
    QgsDebugMsg( msg );
    pushError( msg );
    return false;
  }


  for ( QgsFeatureList::iterator it = flist.begin(); it != flist.end(); ++it )
  {
    attrs = it->attributes();

    int fieldIdx = 0;
    if ( copyOperation )
    {
      fieldIdx = 1;  // skip first (FID) field if copying from shapefile
    }
    int bindIdx = 0;
    for ( int i = 0; i < attrs.count(); i++ )
    {
      QgsField fld = mAttributeFields.at( fieldIdx++ );
      if ( fld.name().isEmpty() )
        continue; // invalid

      if ( mFidColName == fld.name() )
        continue; // skip identity field

//      if ( mDefaultValues.contains( i ) && mDefaultValues[i] == attrs.at( i ) )
//        continue; // skip fields having default values

      QVariant::Type type = fld.type();
      if ( attrs.at( i ).isNull() || !attrs.at( i ).isValid() )
      {
        // binding null values
        if ( type == QVariant::Date || type == QVariant::DateTime )
          query.bindValue( bindIdx,  QVariant( QVariant::String ) );
        else
          query.bindValue( bindIdx,  QVariant( type ) );
      }
      else if ( type == QVariant::Int )
      {